1. Field of the Invention
The present invention relates to a transmitter and a receiver, and more particularly, to a transmitter and a receiver of a display.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a diagram illustrating a transistor-transistor logic (TTL) interface 100. As shown in FIG. 1, the interface 100 includes a transmitter 110 and a receiver 120, where the receiver 120 receives a digital signal via a single data line L. The TTL interface 100 has good noise immunity; however, the digital signal generally requires a large swing, therefore electro-magnetic interference (EMI) is serious and an operating frequency is limited.
To solve the EMI and operating frequency issues in the TTL interface 100, a circuit for reduced swing differential signaling (RSDS) is utilized. FIG. 2 is a diagram illustrating a prior art circuit 200 for RSDS. As shown in FIG. 2, the circuit 200 includes a transmitter 210 and a receiver 220, where the receiver 220 is coupled to the transmitter 210 via a data line pair. The circuit 200 has better EMI and operating frequency due to smaller swings of signals carried on the data line pair. However, current sources IS1 and IS2 in the transmitter 210 require higher supply currents (about 2 mA) to the data line pair, causing increased power consumption. Furthermore, the number of data lines is doubled compared with the TTL interface 100, which increases the manufacturing cost.